I'm looking for a well documented, easy to use API that provides data on the majority of cryptocurrencies. That data should include the 1 hr, 24hr, and 7 day price changes, as well as the entire history of the volume, and price for each crypto. I've looked into some APIs but none have provided this sort of comprehensive information. There are many great sites that have access to this sort of data, so it must be out there. Any help is appreciated! Thanks!

this real-time data feed provides access to real-time streaming price data from the cash exchanges and liquidity providers for institutional order flow as well as historical database, market metrics, logo API and widgets.

at Kaiko (www.kaiko.com) we are able to provide you with this comprehensive datasets.
We are a market data infrastructure company since our creation in 2014 and provide trade data, order books and aggregated data (ohclv, vwap, count). We already work with funds, academics, and individual traders and are currently growing fast.
Happy to speak with any of you that have data requirements, just contact us via our website.

Almost each crytpo exchange has its own API, you can integrate it for free and get the data. The first challenge that they are too many (more than 200 exchanges so far), that means 200+ API integrations which cost a lot of time. The second challenge is that these exchanges provide a lot of data and after start collecting you will need to take care of many TBs which is an additional servers cost.

That's why there are such services like Coinmarketcapi professional API, coinapi and CryptoAPIs.io

I made a compare and i picked https://cryptoapis.io/ because they have more exchanges, more options and cheaper.